Re: [PATCH V10 net-next 06/10] net: hibmcge: Implement .ndo_start_xmit function
From: Jakub Kicinski <kuba@kernel.org>
Date: 2024-09-15 15:16:29
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On Thu, 12 Sep 2024 10:51:23 +0800 Jijie Shao wrote:
quoted hunk ↗ jump to hunk
+static int hbg_napi_tx_recycle(struct napi_struct *napi, int budget) +{ + struct hbg_ring *ring = container_of(napi, struct hbg_ring, napi); + /* This smp_load_acquire() pairs with smp_store_release() in + * hbg_start_xmit() called in xmit process. + */ + u32 ntu = smp_load_acquire(&ring->ntu); + struct hbg_priv *priv = ring->priv; + struct hbg_buffer *buffer; + u32 ntc = ring->ntc; + int packet_done = 0; + + while (packet_done < budget) {
you should so some cleanup even if budget is 0 in fact you can hardcode the amount of work Tx NAPI does to 128 and don't look at the budget as a limit. Per NAPI documentation budget is for Rx
quoted hunk ↗ jump to hunk
+ if (unlikely(hbg_queue_is_empty(ntc, ntu, ring))) + break; + + /* make sure HW write desc complete */ + dma_rmb(); + + buffer = &ring->queue[ntc]; + if (buffer->state != HBG_TX_STATE_COMPLETE) + break; + + hbg_buffer_free(buffer); + ntc = hbg_queue_next_prt(ntc, ring); + packet_done++; + } + + /* This smp_store_release() pairs with smp_load_acquire() in + * hbg_start_xmit() called in xmit process. + */ + smp_store_release(&ring->ntc, ntc); + netif_wake_queue(priv->netdev); + + if (likely(napi_complete_done(napi, packet_done)))
if packet_done >= budget you should not call napi_complete_done() as you are not done
+ hbg_hw_irq_enable(priv, HBG_INT_MSK_TX_B, true);